#include<iostream>

using namespace std;


class Solution {
public:
    bool lemonadeChange(vector<int>& bills) {
        int five = 0;
        int ten = 0;
        for (auto e : bills) {
            if (e == 5) {
                five++;
            }
            else if (e == 10) {
                if (five == 0)
                    return false;
                else
                {
                    five--;
                    ten++;
                }
            }
            else {
                if (ten > 0 && five > 0) {
                    ten--;
                    five--;
                }
                else if (five >= 3) {
                    five -= 3;
                }
                else
                    return false;
            }
        }
        return true;
    }
};


int main()
{
    return 0;
}